I've had a set of FH3's with fe126en drivers for a little while now and I've been very happy with them. Once 'worn in' the drivers were delivering an excellent range of notes and really low bass, they really were vibrating the room, amazing considering their size however, I've moved house now and all that lovely low frequency stuff and all but vanished.

I will admit, the previous listening room was very good. Laminate floor over solid concrete. The new one is carpet over floor boards.

My amp is a arcam 90.2 however that will get changed for a Tubelabs Simple SE once finished and the sources are a PS3 and Lenco derived TT.

Before they bedded in I was after more bass and looked into seperate sub/s but finding something that works with the fostex's high efficiency and was frugal to build but was also compatible with my amplier was appearing unlikely but once they loosened up I was happy but now I'm back at the beginning again soundwise.

What can I do to get my boom back?

Scottmoose

23rd February 2013 11:10 AM

Depends where they are in the room. With the 126, corner loading is all but mandatory to get reasonable LF gain, & even then it's never going to have large amounts of output on the bottom end except in extremely lively rooms. If they're not in corners & you can change the layout a bit to get them there, then that will help a bit. Otherwise we need to consider other things.

The Arcam amplifier is not really ideal for the FE126En since it has a low output impedance (or high damping factor if you prefer). The 126, like all the En / ESigma Fostex range, was specifically designed for use with high output impedance amplification (SET / DHT, or equivalent single-ended SS designs like those of Nelson Pass). The Tubelabs amp kit should help there. In the meantime, until that's up & running, you don't say what speaker wire you have, but you could swap it out for something like 30ga magnet wire. Just be careful since it's very delicate. Use one strand each to the positive & negative legs. The additional (distributed) series resistance should help matters, and the fact that it's solid core doesn't hurt either. If you want to keep things neat, space them about 1/2in apart between a couple of pieces of tape, or alternatively get some pieces of dowel rod, balsa or whatever, drill a couple of holes in each piece & slide half a dozen or so along each pair to keep them together & give a little extra mechanical support. You can do the same with 'larger' gauges like a pair of 24ga conductors extracted from a run of Cat5, but the lower resistance will provide less compensation. With thin conductors like these, keep an eye that they don't heat up too much (obviously), and take care not to scratch through the enamel insulation (except at the ends of course ;) ).

Beyond that, we're into changing drive units for something with more LF output, e.g. the Mark Audio CHR / CHP / Alpair 7 units, or one of the 4in Tang Band models e.g. the W4-1320.

The wire I'm using is QED silver anniversary so there's an area I can work on, I'll give that a try. I forgot to mention the cabinets are 18mm MDF, not ply (funds etc) and the additional tweeters I'm using (CSS tweeters, I used them following a thread on here somewhere) if that makes any difference. I have a simple inline resistor to cut out all but the highest frequencies to add a little sparkle.

In light of your suggestions I'll get the other amp up and running asap and see how it sounds after that. Failing that, as you say maybe another driver is in order.

Such a shame as in the previous room, for me and my neighbours bass was not lacking. They didn't shake any foundations but I was rarely left wanting for more LF punch.

Is their, a low cost diy sub type enclosure (is the fh stealth sub up and running?) that can be used with the high efficiency fostex drivers and also a 2 channel amp (I don't want/can't have an additional amp i the picture)?. I know similar questions have been asked before but none exactly the same as mine.

I ask the above as I've been wanting to apply the enabl process to my drivers as I like the sound of the benefits but not the reported slight reduction in bass and I'd like to loose the tweeters idealy and enabling could be the answer. I really don't need much LF assistance, just a wee bit.

xrk971

23rd February 2013 12:51 PM

Quote:

Originally Posted by mudchute
(http://www.diyaudio.com/forums/full-range/230698-fh3-ive-moved-house-sound-awesome-post3382693.html#post3382693)

Is their, a low cost diy sub type enclosure (is the fh stealth sub up and running?) that can be used with the high efficiency fostex drivers and also a 2 channel amp (I don't want/can't have an additional amp i the picture)?. I know similar questions have been asked before but none exactly the same as mine.

I ask the above as I've been wanting to apply the enabl process to my drivers as I like the sound of the benefits but not the reported slight reduction in bass and I'd like to loose the tweeters idealy and enabling could be the answer. I really don't need much LF assistance, just a wee bit.

I have been working on a design for a fourth order vented sub with the $9 Aura NS6 driver that should have 87 db to 90db output from 40 to 100 Hz using acoustic crossover so no coil xover needed. If you run it in parallel with your fostex, that can drop impedance to match your amp better. The analysis is on the the Acoustic Crossover on a budget thread. I have not built it yet, but it may work for your application.

MDF won't make any difference to the quantity of LF output. The ruddy great hole in the wall to the left (doorway / arch?) isn't likely to help matters, but since you still have a degree of corner loading and the room doesn't appear over-damped (internal dry stud walls or similar however are notorious for leaching LF so if you have any of those they might be a problem) you're back to changing equipment. The amplifier will almost certainly help. In the meantime junk that QED wire for something with higher resistance which should help a bit, preferably the 30ga magnet wire I mentioned.

An series resistor to high pass the tweeter? I think you might mean a capacitor? You don't say what model, but it looks like Colin's idea of stuffing the ERT26 into a small cylinder for convenient top-mounting. A cap is only going to give a 1st order rolloff, so if you set an XO frequency of, say, 15KHz it's only going to be -6dB at 7.5KHz where the 126 is still cranking out lots of energy, so you may want to look at either a higher XO frequency or a steeper slope, which should make the LF a little more prominant.

EnABL to the best of my knowledge doesn't cause any LF losses. Since you've added mass to the cone, however minor, it will result in a minor loss of efficiency / sensitivity however. Nothing to get too worked up about though.

Otherwise, as I say, you're probably going to need to swap out the drivers for something that gives more output on the bottom end, e.g. the MA drivers or one of the 4in Tang Band units. If nothing else, this is a classic example of how critical system / room-matching can be, and how the listening space itself dominates < 300Hz.

tinitus

23rd February 2013 01:28 PM

sorry, but your room looks to me like a 'shouter room' with lots of 'echo' and other 'effects'

jrenkin

23rd February 2013 02:25 PM

Quote:

Originally Posted by mudchute
(http://www.diyaudio.com/forums/full-range/230698-fh3-ive-moved-house-sound-awesome-post3382567.html#post3382567)

I will admit, the previous listening room was very good. Laminate floor over solid concrete. The new one is carpet over floor boards.

What can I do to get my boom back?

It sounds like your old room had hard surfaces, especially the floor, and likely had a significant resonance at bass frequency that you learned to like. Your new space has a better damped floor and is missing part of a wall, so room effect are less and fail to augment the bass in the manner you have become accustomed to.
You probably have more natural sound in the new room, but if you want the bass to stand out again, you will need a woofer. The speaker cabinet enhances some LF around where it is tuned, but, especially with that driver, relies heavily in room augmentation.

tinitus

23rd February 2013 02:36 PM

maybe you could use a BIB speaker now :D

mudchute

23rd February 2013 04:01 PM

Well, its actually very quiet. The previous room had little corner loading. One corner was wall/big front window type wall and the other corner was only 10" deep in one side thanks to a rebate(?).

This one has actual bricked corners for the speakers to sit in. As Jrenkin says though the sound absorbing carpet in this one etc just sucks the bass out of whats being generated and before, amplified it without being boomy.